Strosser U.S. Pat. No. 4,624,180 discloses a microprocessor-based control circuit for controlling a rectangular baler so that bales of crop material of uniform density are produced. It is conventional to provide rectangular balers with knotters, as illustrated in U.S. Pat. No. 3,416,824. After sufficient crop material to form a bale has been compacted, knotters encircle the bale with a loop of twine, tie a knot in the loop, and cut the loop from the twine supply. A knotter station usually has several knotters, the exact number being determined by the size of the bales produced by the baler.
The above-referenced copending application of Jackson discloses a mistie detector for detecting when a knotter fails. However, the mistie detection switch disclosed in that application produces two output signals on each knotter cycle. One signal is produced each time a knotter cycle is initiated and another signal is produced at the time the knot is pulled from the knotter if the knotter properly tied a knot in the loop surrounding the bale.